#include "stdio.h"
#include "string.h"
extern int mywrite(int fd, const char *buf, int len); 
extern int myadd(int a,int b,int* res);
int main()
{

    char buf[1024];
    int str,des,res;
    char* mystr ="Calculating...\n";
    char* emsg = "Error in adding\n";
    str = 5;des = 11;
    mywrite(1,mystr,strlen(mystr));
    if(myadd(str,des,&res))
    {

        sprintf(buf,"the result is %d\n",res);
        mywrite(1,buf,strlen(buf));

    }
    else
    {
        mywrite(1,emsg,strlen(emsg));
    }
    return 0;

}